1. Field of the Invention
The invention relates to a condensate discharge device including a housing formed with a flow chamber, which has inlet and outlet pressure regions, a valve seat disposed in the inlet pressure region, a closure part cooperating with the valve seat so as to be able to rest thereon, a float disposed in the chamber and movable along a stroke distance, and lever means connecting the float with the closure part, and having a force transmission ratio in dependence of the stroke distance.
2. Description of the Prior Art
Condensate discharge devices controlled by a float make use of the density difference between the condensate and the vapor. A buoyant force generated by the condensate and acting on the float is transmitted through a lever mechanism to a closure part. The closure part is either opened or closed by the vapor forces acting thereon. Since the buoyant force is relatively small, condensate discharge devices controlled by a float are relatively large compared to other condensate discharge devices. Several devices have become known, where, by taking appropriate measures with respect to the closure part, an attempt has been made to reduce the magnitude of the prevailing pressure forces, when the valve begins to open so as to require only a small buoyant force, and hence a small dimension of the device. All of these attempts have failed, particularly in the case of condensate discharge devices having small or medium flow throughputs, as the measures to be taken pertaining to the closure part required a very difficult control of the valve openings. Moreover, the valve openings of these conventional devices are easily clogged in actual operation, even when a small amount of contamination occurs.
When the force acting on the closure part is varied, on one hand, with an increasing pressure difference, while the buoyant force is held almost constant, almost all conventional float controlled condensate discharge devices make use of differently sized closure parts, in order to be able to more efficiently use the available condensate discharge housing over a greater pressure range. In a known device, this disadvantage is somewhat compensated for by the varying the transmission ratio or leverage of the transmission mechanism along the stroke of the float. As the valve begins to open, a relatively large leverage force provided by the transmission mechanism ensures that the closure part will open at a large pressure difference with a relatively small stroke. During the opening stroke, the transmission ratio decreases so that if the pressure difference become smaller, there is a further opening of the valve closure part. Thus, an almost constant throughput can be obtained over the operating pressure of the device. But this construction does not reduce the size of the condensate discharge device.